reported. When the host reads sense data with a REQUEST SENSE, it will see an error for the WRITE with residue information indicating data lost for that write and previous writes.

•If the command is not a write command and the Deferred Error check is performed as part of the pre-execution checks, CHECK CONDITION status is reported. The DEFERRED ERROR sense is copied to Current sense. The DEFERRED ERROR sense is cleared. The host is expected to retrieve the sense by sending a REQUEST SENSE, otherwise the data will be lost.

Bus release deferred errors:

The drive will release the bus to terminate an operation (such as READ) when the host sends an ABORT message or when the drive fails to send status due to a catastrophic error.

In each case, the operation does not terminate immediately since the logical position will have to be established on the other side of the block that was about to be transferred, or was being transferred. If an error subsequently occurs while trying to complete the read, the sense generated is a DEFERRED ERROR. It is therefore possible but highly unlikely to have DEFERRED ERROR sense flagged for a command without immediate report.

Sense keys

The following table lists the sense keys that may be returned by HP Ultrium drives. SCSI sense keys are 4-bit codes returned in the sense data. They indicate in what general area the problem that has just been experienced falls. For a clearer indication of the nature of the problem, refer to the additional sense code.

Code

Name

Description

ASC/Qs

 

 

 

 

0h

NO SENSE

There is no real problem. The sense information is

0000h, 0001h, 0002h,

 

 

probably indicating some condition (such as

8282h

 

 

encountering a filemark).

 

 

 

 

 

 

 

1h

RECOVERED ERROR

Returned if a Mode Select parameter is truncated

5D00h, 3700h

 

 

or if a TapeAlert event is being reported.

 

 

 

 

 

 

 

2h

NOT READY

The drive is not in a state to be able to execute

0400h, 0401h, 0402h,

 

 

the request. See also the Media Access check.

3003h, 3007h, 3A00h,

 

 

 

3E00h

 

 

 

 

3h

MEDIUM ERROR

The command failed, believed to be caused by a

0002h, 0004h, 0407h,

 

 

problem with the tape.

0410h, 0C00h, 1100h,

 

 

 

1102h, 1400h, 3001h,

 

 

 

3002h, 3004h, 3100h,

 

 

 

3B00h, 5000h, 5200h,

 

 

 

5300h

 

 

 

 

4h

HARDWARE ERROR

The command failed, believed to be caused by a

 

 

 

problem with the drive hardware.The FRU in the

0403h, 40XXh, 4400h,

 

 

sense data should indicate which part of the

5100h, 5300h

 

 

hardware is faulty.

 

 

 

 

 

Commands

REQUEST SENSE 03h 157